---
title: "What is Cline?"
description: "An introduction to Cline, your AI-powered development assistant in VS Code."
---

Cline is an open source AI coding agent that brings frontier AI models directly to your VS Code editor. Unlike autocomplete tools, Cline is a true coding agent that can understand entire codebases, plan complex changes, and execute multi-step tasks.

## Open Source AI Coding, Uncompromised

Cline gives you direct, transparent access to frontier AI with no limits, no surprises, and no model ecosystem lock-in. See every decision. Choose any model. Control your costs.

### Complete Transparency

Watch in real-time as Cline reads files, considers approaches, and proposes changes. Every decision is visible, every edit reviewable before it's made. This isn't just "explainable AI" - it's complete transparency.

### Your Models, Your Control

Use Claude for complex reasoning, Gemini for massive contexts, or Qwen3 Coder for efficiency. Switch instantly as new models launch. Your API keys, your choice. No gatekeeping innovation.

### Built for Real Engineering

Cline can:
- **Read and write files** across your entire codebase
- **Execute terminal commands** and debug errors
- **Plan complex features** before writing code
- **Connect to external systems** through MCP servers
- **Understand large codebases** with intelligent context management

## Plan & Act Mode

Cline explores your codebase and works with you to create comprehensive plans before writing a single line of code, ensuring it understands the full context of your project.

**Plan Mode** for complex tasks - Cline explores, asks questions, and creates detailed implementation plans.

**Act Mode** for execution - Cline implements the plan with full transparency and control.

## Zero Trust by Design

Your code never touches our servers. Cline runs entirely client-side with your API keys, making it the only option for enterprises with strict security requirements.

**Open source** means your security team can review every line. See exactly how Cline works, what it sends to AI providers, and how decisions are made.

## Key Features

### Focus Chain
Automatic todo list management with real-time progress tracking throughout your tasks. Keeps Cline on track across long projects.

### Auto Compact
When conversations get long, Cline automatically summarizes to preserve context while freeing up space to continue working.

### Deep Planning
For complex features, Cline investigates your codebase, asks clarifying questions, and creates comprehensive implementation plans.

### MCP Integration
Connect to databases, APIs, and documentation through the Model Context Protocol. Cline becomes your bridge to any external system.

### .clinerules
Define project-specific instructions that Cline follows including coding standards, architecture patterns, or team conventions.

## Why Developers Choose Cline

**100% Open Source** - Every line of code on GitHub. 48k+ stars from developers who've read it, improved it, and trust it with their work.

**No Inference Games** - We don't profit from AI usage. While others limit context or route to cheaper models, we give you unrestricted access to any model's full capabilities.

**Future-Proof by Design** - New model released? Use it immediately. Cline works with any AI provider, any model.

**True Visibility** - See every file read, every decision considered, every token used.

## Getting Started

Ready to experience AI coding without limits? [Install Cline](/getting-started/installing-cline) and start with our [Model Selection Guide](/getting-started/model-selection-guide) to choose the right AI model for your needs.
